Cutting tool attachment for a power hammer

ABSTRACT

A powered panel cutter attachment for a power hammer having an impacter element and including a tubular housing removably attached to the impacter had having a reciprocable plunger oscillatable in a housing which terminates in a substantially Cshaped guide and support foot including a rear guide surface parallel to the path of reciprocation of the plunger and in spaced relation therefrom a T-shaped slot, and in which a tool element body includes opposed, parallel portions reciprocably and guidingly engaged by the respective parallel inner surface and Tshaped slot portions and is detachably connected to the plunger, and in which said tool body terminates in a lower metal-cutting means generally at the axis of reciprocation and below the foot of said housing; the metal-cutting means including on different attachments a cutting element for removing a relatively thin strip of metal, a chisel element and a spot-weld removing element.

3,289,454 12/1966 Chandler United States Patent [72] lnventor Earl Chandler 17211 N.W. 37th Ave., Opa-Locka, Fla. 33054 [21] Appl. No. 821,044

[22] Filed May 1, 1969 [45] Patented May 4, 1971 [54] CUTTING TOOL ATTACHMENT FOR A POWER Primary ExaminerOthell M. Simpson Assistant Examiner-Michael Koczo, Jr.

Attorney-John Cyril Malloy housingremovably attached to the impacter had having a reciprocable plunger oscillatable in a housing which terminates in a substantially C-shaped guide and support foot including a rear guide surface parallel to the path of reciprocation of the plunger and in spaced relation therefrom a T- shaped slot, and in which a tool element body includes opposed, parallel portions reciprocably and guidingly engaged by the respective parallel inner surface and T-shaped slot portions and is detachably connected to the plunger, and in which said tool body terminates in a lower metal-cutting means generally at the axis of reciprocation and below the foot of said housing; the metal-cutting means including on different attachments a cutting element for removing a relatively thin strip of metal, a chisel element and a spot-weld removing element.

PATENTED HAY 4 I97! SHEET 2 [IF 2 CUTTING TOOL ATTACHMENT FOR A POWER HAMMER This invention relates generally to power tools, and, more particularly, to an improved power-operated cutting tool generally designed for use in automobile body repair work or the like.

Typical of the type of power cutting tool and/or power operated tools involved are U.S. Letters Pat. to Clark Chandler, Nos. 3,056,202 and 3,215,008 as well as applicant's U.S. Letters Pat. No. 3,289,454.

Primary objects of the present invention are:

to provide in a powered panel cutter attachable to a power hammer and operable in a rectilinear path byareciprocable impacter, a novel cutter attachment retained in the guided path of movement;

1 in cross section, in which the cutter attachment includes guide portions complementary to and reciprocably supported in the guide portions of the housing, and the tool element terminating in a lower cutter element substantially disposed in alignment with the longitudinal path of reciprocation of the impacter operating the tool;

to provide tool attachments of the character mentioned above in which one tool attachment incorporates means for removing a relatively thin strip of metal, another tool attachment for chiseling, and a still further attachment for removing spot welds, for example.

These, together with other and more specific objects and advantages of the invention, will become apparent from a consideration of the following description of the exemplary embodiments when taken in conjunction with the drawing forming a part thereof in which:

In the drawing:

FIG. 1 is a perspective view of a power tool illustrating the cutting attachment in a position of use;

FIG. 2 is an enlarged side elevational view;

FIG. 3 is an enlarged side elevational view looking from left to right at the lower portion of FIG. 2;

FIG. 4 is a horizontal section taken substantially along the plane of line 44 of FIG. 2;

FIG. 5 is an-enlarged vertical section taken substantially along the plane of line 5-5 of FIG. I and generally showing the attitude of the tool with respect to a piece of metal to be cut;

FIG. 6 is a view similar to FIG. 5 showing the parts of FIG. 5 at their lower position ofreciprocation and after a portion of the cut has been effected;

' FIG. 7 is a horizontal plan view taken along the plane of line 7-7 of FIG. 5;

FIG. 8 is a view similar to FIG. 5 and showing an alternate embodiment ofthe attachment;

, FIG. 9 is an elevation view looking from left to right at FIG. 8; and

FIG. 10 is a view similar to thelower portion of FIG. 9 and showing an alternative cutting edge for the tool.

Referring to the drawing in detail, in FIG. I, a pneumatically operated power hammer is indicated generally at 10 and comprises a handle 12 operatively connected to a source of air pressure by means of hose I4, a control trigger l6 and a housing 18 in which a power operated impacter (not shown) is reciprocably supported. Although the present embodiment is illustrated with respect to a pneumatically operated tool, the invention can likewise be utilized with electrically operated tools.

The tool includes a longitudinal bore portion 20 and a lower, externally threaded stem portion 22 to which is secured the upper internally threaded portion 24 of a housing 26 which includes an axial, enlarged diameter bore portion 28.

' Reciprocably supported at its other upper end in the bore portion 20 is a cylindrical guide rod portion of a plunger 30 which includes an intennediate annular abutment flange 32 engaged by a compression spring 34 disposed in chamber portion 28. The plunger 30 includes a lower rod portion 36 terminating at its distal end in a slightly tapered portion 38 and projecting through an axial bore 40 of the housing 26.

The housing 26 includes a lower integral support-and-guide foot 42 which is substantially C-shaped in elevation as seen in FIGS. 1 and 2, for example. The guide foot includes a back wall 44 and bottom wall 46 both reinforced by an outwardly projecting, angular rib 48. The back wall includes an inner, planar guide surface 50 which is parallel to the longitudinal axis, i.e., the path of rectilinear movement of the plunger, and the forward portion of the support 42 is open at 52 opposite the back wall 44, and is also open transversely as seen in FIG. 7, for example. In spaced relation from the back wall 44 and at the remote end of the bottom wall 46 is a slightly upwardly extending lip 56 which has extending therein a vertical through slot 58 including a relatively wide transverse portion 60 and a relatively narrower leg portion 62 opening toward the planar inner surface 50 of backwall 44.

A cutting tool element is indicated generally at 64 and comprises a relatively solid upper body portion 66 including a conical socket 68 frictionally retained on the tapered portion 38 of the plunger. Extending transversely through the body portion 66 is a through bore 70; see FIGS. 4 and 5, into which the terminal end of the tapered portion 38 of the plunger extends. Accordingly, a drive pin D (as shown in FIG. 4) can be utilized to separate the tool element 64 from the plunger after the housing 26 has been threadedly disengaged at 24.

The body portion 66 of the tool element includes an inner, planar surface 72 guidingly engaged on the inner surface 50 of the housing support, and the forward portion of the body member 66 incorporates a depending and reinforced portion having a T-cross section 74 (see FIG. 7) which is complementary to the T-cross sectioned slot 58 and which is guidingly and reciprocally received therein. The portion 74 depends below the bottom wall 46 of the housing, and includes an inwardly and angularly directed outer surface 76 extending toward the longitudinal axis of the path of reciprocation of the tool element 64, i.e., the plunger. Formed on the planar surface 76 and adjacent the lower end thereof is a triangular cutting portion 78 which merges from the surface 76 and terminates in a lower arcuate surface 80. The cutting element 78 includes planar or parallel sidewalls 82 and 84, and it will be noted that surface 76 generally defines a continuation of the arcuate surface 80 below the transversely arcuate edge of portion 74.

Referring to FIGS. 1, 5 and 6, the metal M to be cut will have a slight intermediate slot formed therein and/or one can start a cut at the edge of the metal. The cutting element 78 will be disposed beneath the surface of the piece of metal and trigger I6 of the power tool will be depressed, accordingly causing reciprocation of the impacter and plunger. As cutting tool element 64 is reciprocated, the lower portion 74 of the tool serves as a guide and a relatively thin strip of metal, i.e., approximately the distance between parallel sides 82 and 84 will be removed from the metal panel M. As will be observed in FIG. 6, for example, as the strip S of metal is removed, it is rolled off beneath the arcuate undersurface 80 of the cutting manner as the previously described tool element 64. However,

the lower portion of the tool element 64' includes a relatively abbreviated guide rib 74' and the outersurface i.e., the transverse portion of the T-shaped cross section of the tool, cornprises an essentially rectangular plate portion 76' terminating in a transverse chisel edge 78'. The manner in which the tool element 66 is utilized is substantially the same as that of the previous embodiment; however, the chisel edge 78' can be used to initially form a slot or notch in a piece of metal M to accommodate the cutting element 78 of the tool 64, for example.

Referring to H6. 10, the lower portion 76" of still another tool element is illustrated, and in this embodiment the lower chisel edge 78", is interrupted by an intermediate notch portion' 80' which facilitates the use of this tool in the removal of spot welds or the like, for example.

l claim:

l. A powered panel cutter or the like for attachment to a power hammer having an impacter element comprising, in

combination:

a tubular housing having means at one end for removable attachment of the same to the power hammer;

a plunger reciprocable in said housing and drivable on a driving stroke by said impacter element, spring means in said housing for efiecting a return stroke of said plunger;

the improvement wherein, said housing includes, a lower, integral support-and-guide foot comprising a C-shaped portion having a back wall inner surface parallel to the path of reciprocation of said plunger;

a lower foot portion terminating in a T-shaped through slot parallel to the inner surface of said back wall; and

a cutting tool having a body portion including a socket removably received on said plunger for reciprocation therewith; said tool body portion including an inner surface reciprocably received on said back wall inner surface; said tool body portion including a T-shaped outer rib complementary to and reci'procably received transversely through said T-shaped slot of said foot portion for guided engagement in a rectilinear path of movement;

i said outer rib projecting below said housing foot portion. i

and inwardly angularly toward the axis of reciprocation of said plunger; 1 r i said rib portion including, below said foot portion, metal cutting means. i

2. The structure as claimed in claim 1 in which said metalcutting means comprises a planar surface, and a longitudinally v a strip of metal is severed and removed from a sheet of metal when the tool is used.

4. The structure as claimed in claim 1 in which said metalcutting means comprises a lower, transverse, sharpened chisel-edge at the distal edge of said rib below the foot portion.

5. The structure as claimed in claim 4 in which said chiseledge includes an intermediate notch portion for facilitating removal of spot welds or the like.

6. The structure as claimed in claim 1 in which said metalcutting means is disposed substantially in alignment with the longitudinal axis of reciprocation of said plunger whereby force applied by said metal-cutting means is insubstantial alignment with the path of reciprocation of said plunger. 

1. A powered panel cutter or the like for attachment to a power hammer having an impacter element comprising, in combination: a tubular housing having means at one end for removable attachment of the same to the power hammer; a plunger reciprocable in said housing and drivable on a driving stroke by said impacter element, spring means in said housing for effecting a return stroke of said plunger; the improvement wherein, said housing includes, a lower, integral support-and-guide foot comprising a C-shaped portion having a back wall inner surface parallel to the path of reciprocation of said plunger; a lower foot portion terminating in a T-shaped through slot parallel to the inner surface of said back wall; and a cutting tool having a body portion including a socket removably received on said plunger for reciprocation therewith; said tool body portion including an inner surface reciprocably received on said back wall inner surface; said tool body portion including a T-shaped outer rib complementary to and reciprocably received transversely through said T-shaped slot of said foot portion for guided engagement in a rectilinear path of movement; said outer rib projecting below said housing foot portion and inwardly angularly toward the axis of reciprocation of said plunger; said rib portion including, below said foot portion, metalcutting means.
 2. The structure as claimed in claim 1 in which said metal-cutting means comprises a planar surface, and a longitudinally disposed cutter element extending laterally from an intermediate portion of said planar surface.
 3. The structure as claimed in claim 2 in which said cutter element is substantially triangular when viewed in side elevation and merges at its upper end into the planar surface, the undersurface of said cutter element being arcuate, said cutter element including planar, parallel sides whereby a strip of metal is severed and removed from a sheet of metal when the tool is used.
 4. The structure as claimed in claim 1 in which Said metal-cutting means comprises a lower, transverse, sharpened chisel-edge at the distal edge of said rib below the foot portion.
 5. The structure as claimed in claim 4 in which said chisel-edge includes an intermediate notch portion for facilitating removal of spot welds or the like.
 6. The structure as claimed in claim 1 in which said metal-cutting means is disposed substantially in alignment with the longitudinal axis of reciprocation of said plunger whereby force applied by said metal-cutting means is in substantial alignment with the path of reciprocation of said plunger. 